In air-cooled air-conditioning apparatuses in which reheating is performed using air in a heat source side heat exchanger, frost may attach to the heat source side heat exchanger during heating operation, and therefore it is common to periodically perform defrosting operation. Defrosting operation is performed by switching the flow path of a four-way valve to the heat source side heat exchanger side, and therefore a heating operation by a use side heat exchanger cannot be performed during defrosting operation.
In order to solve this problem, a circuit and control method of an air-conditioning apparatus that performs a defrosting operation while continuing heating operation have been proposed (see Patent Literature 1).